U.S. patent number 7,507,045 [Application Number 12/202,616] was granted by the patent office on 2009-03-24 for multiple attitude low paper sensor mechanism.
This patent grant is currently assigned to International Business Machines Corporation. Invention is credited to Richard H. Harris, Dean F. Herring, Tsuyoshi Sanada.
United States Patent |
7,507,045 |
Harris , et al. |
March 24, 2009 |
Multiple attitude low paper sensor mechanism
Abstract
A low paper sensor mechanism for a printer includes two paper
supports. Each paper support includes a fixed roller rotatable
about a fixed roller axis and a movable roller rotatable about a
movable roller axis and pivotable about the fixed roller axis from
a start position to an end position, the movable roller and fixed
roller spaced a predetermined distance apart and capable of
supporting a paper supply roll. A detection device includes a
sensor having an emitting element and a detecting element disposed
in a line of sight of the detecting element. The movable roller is
translatable from the start position toward the end position as a
diameter of the paper supply roll decreases to less than or equal
to the predetermined distance thereby allowing the paper supply
roll to fall between the fixed roller and the movable roller
thereby restoring the line of sight.
Inventors: |
Harris; Richard H. (Raleigh,
NC), Herring; Dean F. (Youngsville, NC), Sanada;
Tsuyoshi (Lihilitho Rise, SG) |
Assignee: |
International Business Machines
Corporation (Armonk, NY)
|
Family
ID: |
40457112 |
Appl.
No.: |
12/202,616 |
Filed: |
September 2, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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12140638 |
Jun 17, 2008 |
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Current U.S.
Class: |
400/613;
242/595.1 |
Current CPC
Class: |
B41J
11/0075 (20130101); B41J 11/0095 (20130101); B41J
15/02 (20130101); B65H 26/08 (20130101); B65H
2301/41386 (20130101); B65H 2553/412 (20130101) |
Current International
Class: |
B65H
26/08 (20060101); B41J 15/02 (20060101); B41J
15/04 (20060101); B65H 26/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Colilla; Daniel J
Attorney, Agent or Firm: Cantor Colburn LLP Piche; Jason
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser.
No. 12/140,638, filed Jun. 17, 2008, the disclosure of which is
incorporated by reference herein in its entirety.
Claims
What is claimed is:
1. A low paper sensor mechanism for a printer comprising: two paper
supports, the first paper support supportive of a paper supply roll
when the printer is mounted to a substantially horizontal surface
and the second paper support supportive of the paper supply roll
when the printer is mounted to a substantially vertical surface,
each paper support including: a fixed roller rotatable about a
fixed roller axis; a movable roller rotatable about a movable
roller axis and pivotable about the fixed roller axis from a start
position to an end position, the movable roller and fixed roller
spaced a predetermined distance apart and capable of supporting a
paper supply roll; and a biasing member in operable communication
with the movable roller and capable of biasing the movable roller
toward the end position; and a detection device including: a sensor
having an emitting element and a detecting element, the emitting
element being disposed in a line of sight of the detecting element;
a paddle assembly having two paddles, one paddle extending beneath
each paper support from a central bar and a trip arm extending from
the central bar; and a paddle biasing member disposed to bias the
trip arm to disrupt the line of sight; wherein the movable roller
is translatable from the start position toward the end position as
a diameter of the paper supply roll decreases to less than or equal
to the predetermined distance thereby allowing the paper supply
roll to fall between the fixed roller and the movable roller thus
exerting a force on one paddle of the two paddles causing the
paddle assembly to rotate about a bar axis thereby restoring the
line of sight.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to printers and, more
particularly, to low paper sensor mechanisms for printers.
2. Description of the Background
Presently, there are several different types of printers available.
However, all printers share common components, such as a print
head, a platen, a paper supply and a control mechanism. The control
mechanism controls a motion of the print head relative to the paper
supply, selects a character to be printed, and advances the paper
supply, as necessary.
Regardless of the type of printer used, it is generally undesirable
to operate a printer without paper. For example, ink-based printers
that are operated without paper will transfer ink into the platen,
which may, in turn, stain a back side of subsequent sheets of paper
and may also damage print writes within the print head. Also,
thermal printers that are operated without paper may overheat,
since the paper is also used to absorb heat generated by the print
head during printing operations. In addition, operating thermal
printers without paper may cause excessive wear to the print head,
since the print head would be running directly on the platen,
instead of on the paper.
Therefore, in order to avoid operating the printers without paper,
conventional printers have been provided with low-paper sensing and
warning systems. Low paper sensing has recently become an important
requirement, as retailers move towards system management, which
requires system notification that a paper supply is near
completion. Further, as printers are at times wall mounted, and at
other times table mounted, printer having a low paper sensor
mechanism which operates whether the printer is in a wall mounted
orientation or in a table mounted configuration would be well
received in the art.
SUMMARY OF THE INVENTION
The shortcomings of the prior art are overcome and additional
advantages are provided by a low paper sensor mechanism for a
printer including two paper supports, the first paper support
supportive of a paper supply roll when the printer is mounted to a
substantially horizontal surface and the second paper support
supportive of the paper supply roll when the printer is mounted to
a substantially vertical surface. Each paper support includes a
fixed roller rotatable about a fixed roller axis and a movable
roller rotatable about a movable roller axis and pivotable about
the fixed roller axis from a start position to an end position, the
movable roller and fixed roller spaced a predetermined distance
apart and capable of supporting a paper supply roll. A biasing
member is in operable communication with the movable roller and is
capable of biasing the movable roller toward the end position.
The mechanism includes a detection device including a sensor having
an emitting element and a detecting element, the emitting element
being disposed in a line of sight of the detecting element. The
detection device includes a paddle assembly having two paddles, one
paddle extending beneath each paper support from a central bar and
a trip arm extending from the central bar; and a paddle biasing
member located to bias the trip arm to disrupt the line of
sight.
The movable roller is translatable from the start position toward
the end position as a diameter of the paper supply roll decreases
to less than or equal to the predetermined distance thereby
allowing the paper supply roll to fall between the fixed roller and
the movable roller thus exerting a force on one paddle of the two
paddles causing the paddle assembly to rotate about a bar axis
thereby restoring the line of sight.
Additional features and advantages are realized through the
techniques of the present invention. Other embodiments and aspects
of the invention are described in detail herein and are considered
a part of the claimed invention. For a better understanding of the
invention with advantages and features, refer to the description
and to the drawings.
TECHNICAL EFFECTS
As a result of the summarized invention, technically we have
achieved a solution which precisely detects a low paper condition
utilizing the same detection device whether the printer is mounted
on a horizontal surface or on a vertical surface.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The subject matter which is regarded as the invention is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
objects, features, and advantages of the invention are apparent
from the following detailed description taken in conjunction with
the accompanying drawings in which:
FIG. 1 is a cross-sectional view of a horizontally-oriented
printer;
FIG. 2 is a cross sectional view of the printer of FIG. 1 with a
partially depleted paper supply roll;
FIG. 3 is a cross-sectional view of a vertically-mounted
printer;
FIG. 4 is a cross-sectional view of the printer of FIG. 3 with a
partially depleted paper supply roll; and
FIG. 5 is a perspective view of a detection device for the
printer.
The detailed description explains the preferred embodiments of the
invention, together with advantages and features, by way of example
with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a printer 10 includes a housing 12 which
contains a paper supply roll 14. The paper supply roll 14,
including a core 16 and a length of paper sheet 18 wrapped around
the core 16, has a first diameter D1. During operation of the
printer, as shown in FIG. 2, an amount of paper sheet 18 wrapped
around the core 16 decreases as the paper supply roll 14 rotates
about a supply roll axis 20 such that the first diameter D1
decreases to a second diameter D2.
The printer 10 is configured so that a base 22 of the printer 10
rests on a mounting surface 24. In some embodiments, the mounting
surface 24 may be, for example, a table or desk such that the
printer 10 is generally oriented horizontally. In other
embodiments, as shown in FIG. 3, the mounting surface 24 is, for
example, a wall such that the printer 10 is generally oriented
vertically.
Referring again to FIG. 1, the printer 10 includes two paper
supports 26a, 26b. The two paper supports 26a, 26b are
substantially identical, so for the sake of brevity, the structure
of one paper support 26 will be described herein. Each paper
support 26 includes a fixed roller 28 fixed to the housing 12 and
rotatable about a fixed roller axis 30. A movable roller 32 is
disposed in the housing and located at a predetermined distance L
from the fixed roller 28 via, for example, at least one connecting
link 34 which extends from the fixed roller axis 30 to a movable
roller axis 36. Thus, the movable roller 32 is rotatable about the
movable roller axis 36 and movable about the fixed roller axis 30
at the distance L between a start position 38 and an end position
40. The movable roller 32 is biased toward the end position 40 by a
biasing member 42, which in some embodiments is a spring.
Paper support 26a is disposed in the housing 10 such that when the
printer 10 is located on a horizontal mounting surface 24, as shown
in FIG. 1, the paper supply roll 14 is positioned in the housing 12
by gravity such that an outer surface 44 of the paper supply roll
14 is maintained in contact with the fixed roller 28 and the
movable roller 32 of paper support 26a while paper sheet 18 is
drawn from the paper supply roll 14 during operation of the printer
10. Similarly, when the printer 10 is located on a vertical
mounting surface 24, as shown in FIG. 3, the paper supply roll 14
is positioned in the housing 12 by gravity such that the outer
surface 44 of the paper supply roll 14 is maintained in contact
with the fixed roller 28 and the movable roller 32 of paper support
26b while paper sheet 18 is drawn from the paper supply roll 14
during operation of the printer 10.
As shown in FIG. 1, when the paper supply roll 14 has a diameter
D1, the mass of the paper supply roll 14 and gravity exert a force
F on the fixed roller 28 and the movable roller 32 to overcome a
bias force exerted by the biasing member 42 such that the movable
roller 32 remains at the start position 38. During operation of the
printer 10, paper sheet 18 is drawn from the paper supply roll 14,
thereby reducing the diameter of the paper supply roll 14 from D1
toward D2, as shown in FIG. 2. As the diameter reduces from D1 to
D2, a magnitude of the force F on the movable roller 32 is reduced
due to a reduction of mass of the paper supply roll 14, and allows
the movable roller 32 to move from the start position 38 toward the
end position 40. When the paper supply roll 14 diameter is equal to
or less than the distance L between the movable roller 32 and the
fixed roller 28, the paper supply roll 14 is allowed to fall
between the fixed roller 28 and the movable roller 32. It will be
appreciated that while this has been illustrated with printer 10 in
a substantially horizontal position and the paper supply roll 14
resting on paper support 26a, the printer 10 functions identically
with the printer 10 in a substantially vertical orientation and the
paper supply roll 14 resting on paper support 26b, as shown in
FIGS. 3 and 4.
As best shown in FIG. 5, the printer 10 includes a detection device
46 which includes, in some embodiments, a sensor 48 and a paddle
assembly 50. The paddle assembly 50 includes two paddles 52
extending from a pivot bar 54. The paddle assembly 50 is disposed
in the housing 12 such that each paddle 52 extends beneath a paper
support 26, and is rotatable about a bar axis 56. A paddle trip arm
58 extends from the pivot bar 54 toward the sensor 48. The sensor
48 includes an emitting element 60 and a receiving element 62 which
are disposed in a line-of-sight 64 of each other, such that an
optical beam, for example, may be emitted from the emitting element
60 and received by the receiving element 62.
The paddle trip arm 58 is biased to a home position, as shown in
FIG. 5, which disrupts the line-of-sight 64 by a paddle bias
element 66, which in some embodiments is a spring. When, as
described above, the paper supply roll 14 allowed to fall between
the fixed roller 28 and the movable roller 32 of either paper
support 26a or 26b, the paper supply roll lands on of the two
paddles 52. The paper supply roll 14 exerts a force on the paddle
52 sufficient to overcome a biasing force of the paddle bias
element 66, thus rotating the paddle assembly 50 about the bar axis
56. When the paddle assembly 50 rotates a sufficient amount, the
paddle trip arm 58 rotates out of the line-of-sight 64 thereby
triggering the sensor 48 to indicate a low paper condition.
While the preferred embodiments to the invention have been
described, it will be understood that those skilled in the art,
both now and in the future, may make various improvements and
enhancements which fall within the scope of the claims which
follow. These claims should be construed to maintain the proper
protection for the invention first described.
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